The Chemical Reactions and Pathways Involving Any Pyrimidine Nucleoside One of a Family of Organic Molecules Consisting of a Pyrimidine Base Covalently Bonded to Ribose (a Ribonucleoside) or Deoxyribose (a Deoxyribonucleoside).

Any Process That Results in a Change in State or Activity of a Cell (in Terms of Movement Secretion Enzyme Production Gene Expression Etc.) As a Result of a Stimulus Indicating Damage to Its DNA From Environmental Insults or Errors During Metabolism.

The Chemical Reactions and Pathways Including Anabolism and Catabolism by Which Living Organisms Transform Chemical Substances. Metabolic Processes Typically Transform Small Molecules But Also Include Macromolecular Processes Such As DNA Repair and Replication and Protein Synthesis and Degradation.

Catalysis of the Transfer of a Group E.g. a Methyl Group Glycosyl Group Acyl Group Phosphorus Containing or Other Groups From One Compound (generally Regarded As the Donor) to Another Compound (generally Regarded As the Acceptor). Transferase Is the Systematic Name For Any Enzyme of EC Class 2.